Question

The main axis forms a cup-shaped receptacle with a narrow terminal opening. Flowers are arranged in cymose within the cup. The description refers to
A) Syconus
B) Cyathium
C) Hypanthodium
D) Verticillaster

Answer 1

In angiosperms, a hypanthium or also called a floral cup is a structure where the basal portions of the calyx, the corolla, and also the stamens form a cup-shaped tube. It is sometimes called a floral tube, which is a term that is also used for corolla tube and the calyx tube. It is present in most of the flowering species even though it varies in structural dimensions and appearance.

Complete answer:
In Hypanthodium the receptacle is considered to be fleshy and it also forms a hollow ball like structure with an apical opening. Three types of flowers develop on the inner surface of the receptacle. The female flowers are towards the base while the male flowers are towards the orifice and the short styled sterile female flowers are in between. The inflorescence is pollinated by a gall wasp.
Syconium is a type of inflorescence which is borne by the figs, which is formed by an enlarged, fleshy, hollow receptacle with multiple ovaries on its inside surface. In short, it is really a fleshy stem with numerous flowers, so it is considered both a multiple and also an accessory fruit.
A cyathium is a specialised pseudanthia which stands for false flowers which forms the inflorescence of plants in the genus Euphorbia.
Verticillaster stands for false whorl.

Therefore, the correct answer is option C) which is Hypanthodium.

Note:
Cymose inflorescence is a type of flowering shoot in which the first formed flower comes from the growing region at the top of the flower stalk. Thus we can say that no new flower buds can be produced at the tip and other flowers are produced from lateral buds beneath.